Lever-ratchet gear



- C. SCHURMANN.

LEVER RATCHET GEAR. APPLICATION FILED AUG-2B. 1919.

Patented Nov; 21, 19 22,

2 SHEET SSHEET 1-.

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C. SCHURMANN.

LEVER RATCHET GEAR.\

. APPLICATION FILED AUG.28, 191s.

Patented Nov. 251, 1922 2 SHEETSSHEET 2,

'1 A8 GAQTi Petented Nov. 21,

CARL SCH'U'RMANN, OF DUSSELDORF, G-ERMALY.

Application filed itugust 28 To all -w 710m it may concern Be it known that I, CARL SCHI'JR ANN, a citizen of the German Republic, and residing at Dusseldorf. Germany, ,haveinvent ed certain new and useful Improvements in Lever-Ratchet Gears, of which the following 5 is a'specification.

The present invention relates to a lever ratchet gear for tools and machine-tools.- The features of the gear according to the present invention are a very simple construction and a silent operation without any play in the feed direction. The gear will never fail and is subject to practically no wear whatever.

The new ratchet-gear according to the, present invention consists essentially of 'a coiled spring which is coupled to two parts movable relatively to each other, of which parts at least'one is of a round shape and frictionally cooperates with its cylindrical surface with the cylindrical surface of the said coiled spring, whilst the other part is rigidly attached to the said spring. The one of said parts is attached to the operating lever, whilst the other part is coupled to the tool or machine part to be operated. The spring allows of moving the operating lever freely in one direction, by said spring gliding with its surface on the round part. lWhen the lever is swung in the opposite sense, the spring will, however, press against the wall of the said round part whereby a heavy friction is produced which. couples this part with the spring and effects the operation of tool or the like by means of the lever.

Tn'the accompanying drawing the ratchet is shown by way of example.

1 shows the various parts of the gear. 2 is a longitudinal section through the Fig. 3 is a cross section on the line in Fig. '2. Fig. t illustrates a twist drill in combination wi h the new" gear, partly in elevation, partly in section.

The sleeve Z) having a square bore a is ected to a second shorter sleeved, or, l in onepiece with thesaine.

placed coiled so LEVER-RATCHET GEAR.

, 1919. Serial is. 320,545.

than the bore of the sleeves (Z and 9 so that it has a tightfit in the same.

The square bore is fitted onto the machine part or the tool, respectively, to be operated. When the lever Z) is swung in the one sense, the spring f will be contracted, whilst it will expand whenthe said lever is swung in the opposite sense. The movement within the spring is naturally but a small one. If the spring has a right hand turn; the sleeve 9 will glide 'over the outer surface of the spring when the lever h is swung to the left, and the tool fitted in the square hole will re main stationar When, thereupon, the lever 7b is swung to the right, the friction between the sleeve and the outer surface of the spring will tend to uncoil the spring, so that the latter will be pressed more and more tightly against the inner wallof the sleeve 6 andthereby the friction is increase B such means the spring is seized by the sleeve. In the same manner, on the lever being swung to the right, the friction between the sleeve ti and the spring will tend to uncoil the latter, so that also here the pressure between spring and sleeve is increased'in such a .manner, that the tool in the bore a is turned-in the same sense. v

instead of the bore a being square, the part I) may also have an eccentric ,stud which engages in a correspondingly ecpentri c bore in thepart to be operated.

Withthe handp'ower drill shown in Fig. ft, the drill 7b is fitted into sleeve Z in which it The other end of the sleeve Z has a female thread a, into which screws a screw 0, which has a hexagonal ead p and a center point 7 On this sleeve Z is freely revolubly titted anotlie sleeve s,

which on one side bears against a flange tof sleeve Z, and on the other side held in posi' ion by a spl t which is secured by aid 0 with w in the sleeve Z.

the sleeve Z ant oiled sprin nt over a Egg is detachably held in known manner by u .ineans of a cotter m.

stationary,

an abutment so that the point of the drill is pressed against the work. the cut of the tool the latter is fed by unscrewing the screw 0 troni'the sleeve Z. M a left hand coiled spring a: is employed, and the sleeve 8 is turned to the right by means otthe handle 2, the friction between sleeve d and spring a: will tend to uncoil the latter whereby the friction between spring and sleeve is increased so that the moving sleevewill grip the spring and carry it along; Owing to its end beingengaged in the sleeve Z, the spring 'will, then drive the said sleeve Z and with; it the drill; ll hen the sleeve 8 is, by aid of its handle turned to the left, the small friction between sleeve 8 and spring a: will coil up the latter a little, so that the friction between the said two parts is so far reduced that the sleeve guides over the spring. l i hen, therefore the sleeve 8 is turned in this sense, the drill will remain The same effect of the spring is secured if, instead of itsouter surface JErictioning with the surrounding sleeves its inner surface coacts with a pin within the spring.

' Whenturned in the sense, which tends to contract the spring, the latter will drive the other part, whilst when turned in the 0pposite sense, the spring; will tend to uncoll and will lift off from the pin so far that the two parts will glide on each other.

The part to lie-operated may also be rig- According to idly attached to the corresponding part of the gear.

I claim:

In a manually operated tool, the combination of an inner sleeve provided with an axial recess forthe reception of the element to be manipulated by said tool, an integral flange. extending about said inner sleeve, an

outer sleeve fitted exteriorly upon said inner sleeve and rotatably mounted thereon said outer sleeve including a circumterential flange spaced from and surrounding said 1;

inner sleeve and bearing against the inteerai flange thereof, av collar fixed'npon the I sleeve and extending over the? outer sleeve to prevent axial separation or said sleeves a coil spring surrounding said inner sleeve within the circumferential flange of said outer sleeve, and an operating handle extending radially outward from saith outer sleeve and adapted, when moved in one direction, to expand said spring into contact with said oircun'iferential flange whereby said sleeves are coincidentally rotated, and when, operated in the opposite direction, to contract said spring out of contact with said circumferential flange whereby said outer sleeve is rotated independently of the inner sleeve.

in testimony whereof ,afix'my ture.

Mild? 

